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Scottish Common Sense Philosophy

Thomas Reid is credited with the development of an approach to philosophy that he has identified with "common sense." To some degree, it is part of the basic orientation of all of the thinkers included in this website. It is a distaste for complex philosophic argumentation, as had been prevalent in medieval philosophy, for example. Reid was mostly triggered in this work by a reaction to Hume's publication of a Treatise on Human Nature, where he questions our ability to have a real knowledge of the world, as our knowledge is in the form of ideas. In fairness, it must be said the Hume also dislikes metaphysics. The intention here is not to delve into this topic, but just to provide an introduction through a few key quotations. 

When I perceive a tree before me, my faculty of seeing gives me not only a notion or simple apprehension of the tree, but a belief of its existence, and of its figure, distance, and magnitude; and this judgment or belief is not got by comparing ideas, it is included in the very nature of the perception… Such original and natural judgments are therefore a part of that furniture which nature hath given to the human understanding. They are the inspiration of the Almighty, no less than our notions or simple apprehensions. They serve to direct us in the common affairs of life, where our reasoning faculty would leave us in the dark. They are a part of our constitution, and all the discoveries of our reason are grounded upon them. They make up what is called the common sense of mankind; and what is manifestly contrary to any of those first principles is what we call absurd... When a man suffers himself to be reasoned out of the principles of common sense, by metaphysical arguments, we may call this metaphysical lunacy; which differs from the other species of the distemper in this, that it is not continued, but intermittent: it is apt to seize the patient in solitary and speculative moments; but when he enters into society, Common Sense recovers her authority.[Reid, 1]

Reid's debt to his teacher, George Turnbull, is obvious, as can be seen from this statement by Turnbull:  "It is only such philosophers, who seeking the knowledge of human nature, not from experience, but from I know not what subtle theories of their own invention, depart from common language, and therefore are not understood by others, and sadly perplex and involve themselves."[2]

Some of the controversy between Hume and Reid deals with the nature of human knowledge, which is a topic that in reality has not advanced much even into our times. In the twenty first century there is a great deal of expectation on the prospect of neural studies contributing to our understanding of the human mind, but not much has happened yet. Turnbull envisions this prospect: "Were this dependence of the body and mind more studied, and its effects collected and ranged into proper order; no doubt, we would be able to form a better judgment of it."[3] Reid's comments on the social nature knowledge and language are also thought-provoking and relevant:

A man may understand and will; he may apprehend, and judge, and reason, though he should know of no intelligent being in the universe besides himself. But, when he asks information, or receives it; when he bears testimony, or receives the testimony of another; when he asks a favour, or accepts one; when he gives a command to his servant, or receives one from a superior: when he plights his faith in a promise or contract: these are acts of social intercourse between intelligent beings, and can have no place in solitude. They suppose understanding and will; but they suppose something more, which is neither understanding nor will; that is, society with other intelligent beings. They may be called intellectual, because they can only be in intellectual beings... When language is once learned, it may be useful even in our solitary meditations; and, by cloathing our thoughts with words, we may have a firmer hold of them. But this was not its first intention; and the structure of every language shows that it is not intended solely for this purpose.[4]

The Social Value of Knowledge

A common theme to many of the participants of the Scottish Enlightenment is an appreciation of the social value of knowledge:

The culture of our minds principally  consists in forming opinions about our duty; and in procuring a large store of valuable knowledge about the most important subjects: as indeed all branches of knowledge have some use, and contribute in some measure to happiness, either by the immediate pleasure, or by discovering more fully to us the divine perfections, or enabling us better to know and discharge our duty... All therefore who have abilities and proper opportunities, ought to apply themselves to improve their minds with an extensive knowledge of nature in the sciences... [Hutcheson, 5]

The first thing remarkable with regard to our sphere of activity is, “that our power and dominion encreases with our knowledge.” Our power in the natural world encreases with our knowledge of the natural world. Thus, by the augmentation of our knowledge of the connexions that make the material or sensible world; or, in other words, of the properties of bodies, how much is our empire over sea, air, fire, and every element encreased? when any property of matter becomes known to us, then are we able to render it subservient to some use in life. And therefore in proportion to our advances in the knowledge and imitation of nature, have arts been invented, that are really so many additions to our power and dominion in the sensible world.[Turnbull, 6]

To penetrate the order established in nature ; to emulate this order in works of design and invention; to unfold the principles of estimation, and realize the conceptions of excellence and beauty, in works to be executed by human art, or in the character and mind of the artist himself, is the peculiar province of man; and in his conduct, with respect to it, gives occasion to the most improving exertion of his faculties. [Ferguson, 7]

The Scientific Method

All of the thinkers of the Enlightenment subscribed to the principles of scientific evidence following Francis Bacon, and they tried to base their thinking on experiences, but George Turnbull provides the most detailed commentary on the scientific method as applied to natural science, and he encourages its use in education:

[Natural science] rests on a very firm foundation, since it is sustained not by fanciful hypotheses or unfounded conjectures, but entirely by either Mathematical reasoning or clear and certain experiments and analogy. This is the only method by which a real knowledge of nature could be advanced and developed was described long ago by the most perceptive Verulam [Bacon]. And it is by this method that it has indeed about that this Science has reached such a peak of perfection in our time, especially through the wonderful insight and industry of the most illustrious Newton.  [8]

Show them [students] how air, water, and all the elements,  and almost all bodies, have been rendered subservient to the advantage or conveniency of human society, by the knowledge of their qualities. They will thus be early led at once to perceive the beauty, and taste the pleasure of natural knowledge, and to remark, that the proper business of mankind on earth, is to obtain a large dominion, command, or lordship there, by subduing, as it were, every element, every object to their use, and that by extending their insight into natural causes, i.e. the natural properties of things, and the laws according to which they produce effects.[9] 

Appreciation of Nature

Turnbull, in the best Western tradition, finds that the knowledge of nature is not only of practical value, but it is also pleasurable and inspiring. In the second paragraph, he provides an insight that is food for thought, that the coherence and beauty of the material world would not be complete without beings like us that can appreciate it:

How immense is the variety of the sensible world? Can there be a more delightful, or a more capacious field of study and speculation, than what the riches, the simplicity, the grandeur and perfect order of the natural world afford us? , What is greater, or more elevating than the contemplation of nature, when we are able to take in large views of it, and comprehend its laws? How agreeably do ancient philosophers expatiate upon this topic! The study of nature, according to them, is the natural food of the soul. And they indeed  justly placed a great part of man’s best happiness in contemplating and imitating the regularity, wisdom, goodness and harmony of the sensible world...[10]

But let it be observed before we proceed, that as a material world cannot be said to have order and beauty; or to be wisely contrived, but with respect to beings, who perceive it, and are affected by it... so were there not in nature such a kind of beings as we are, nature could not be full or coherent: there would be a chasm or void in nature which could not but render it deformed and imperfect to the view of any being capable of perceiving it; who hath, like us, any idea of richness, fullness, and perfection in nature...[11] 

The Knowledge Heritage and Progress

Ferguson continues the theme of the social value of knowledge and science, but it is on the subject of the cumulative knowledge heritage and of progress that his comments are most insightful:

Discoveries of science, models of invention, or attainments of genius, wherever they may have originated, find their way to the world, and become the property of mankind... In this species, the communication extends from nation to nation, and from age to age, at any indefinite distance of place or time; and the society, or co-operations of men may be conceived as extended accordingly. The present age is perfecting what a former age began; or is now beginning what a future age is to perfect.[12]

So that the most retired student of nature, in extending the limits of knowledge, works for his community; separate communities mutually work for one another, for ages to come, and for mankind. And attainments in this branch, perhaps more than in any other, may be considered, not as local advantages gained to any particular society of men, but as steps in the progress of the human species itself.[13]


Given the strong academic connection of this movement, it is not surprising to see their celebration of education, as expressed in the following quotation from Hutcheson's  inaugural address to the student body on his installation at Glasgow:

Go forward, then, in virtue, beloved young men, the hope of this generation and the glory, I trust, of the generation to come. Take nature and God as your guide, apply your minds to liberal studies, and lay down a varied store of useful knowledge which you may bring forth one day in all honorable, temperate, modest, and courageous service to our country and the human race.[14]

Ferguson relates education to maintaining and facilitating the knowledge heritage:

So long as the son continues to be taught what the father knew, or the pupil begins where the tutor has ended, and is equally bent on advancement; to every generation the state of the arts and accommodations already in use serves but as ground work for new invention and successive improvement...[15]

Turnbull gives the most attention to this topic, in his Observations Upon Liberal Education. In the quotation below, he reflects on how to motivate students to develop a sense of duty resulting from their education:

Give them an account of the inventors and improvers of arts, and of the manifold advantages we reap from such discoveries, and show them the glory due to them, and cheerfully rendered to them by history, and they will at once see what is the proper employment of human understanding, or wherein its riches and greatness lies, and perceive the application and order of study requisite to attain to equal glory on the account of like usefulness in society, and be fired with zeal to improve their intellectual powers in the same manner; with an antipathy against idleness on the one hand, and fraud or violence on the other, and with love of public order, liberty and justice... And are not the beginnings of this taste and temper the proper first elements or beginnings of education, in the knowledge and duties of man?[16]

The Fine Arts

George Turnbull was very appreciative of the inspirational value of the fine arts, and he laments their limited use in education:

For tho’ truths may be rendered evident and certain to the understanding by reasoning about them, yet they cannot reach our heart, or bestir our passionate part but by means of the imagination. The fine arts are, indeed, but so many different languages by which truths may be represented, illustrated and recommended to us... It is indeed not to be wondered at, considering how egregiously the formation of fancy is neglected in education, that it should be so irregular, desultory and turbulent a faculty, instead of a pleasant, governable and useful one... all the entertaining and embellishing arts of fancy, which give such lustre, beauty and taste to human life; to all the ingenious productions of men of wit and fine imagination: the advances that have been made towards its improvement, to which we owe so many great genius’s, and their delightful productions and compositions.[17]

He also recommends the healing power of music: "very advantageous uses might be made of that art, in several cases, for delivering the mind from disorders; or for purging and refining the passions; calming, quieting, cheering, and strengthning the mind."[18]

[1]Thomas Reid, Essays on the Intellectual Powers of the Human Mind (Dublin: L. White, 1786), Vol.1, 259-260.

[2] George Turnbull, Principles of Moral Philosophy (London: John Noon, 1740), 16.

[3] Ibid.,77.

[4]Thomas Reid, Essays on the Intellectual Powers of the Human Mind, 77-79.

[5] Hutcheson, A Short Introduction to Moral Philosophy (Glasgow: Robert and Andrew Foulis, 1753), 81.

[6] George Turnbull, Principles of Moral Philosophy, 29.

[7] Adam Ferguson, Principles of Moral and Political Science (Edinburgh: W. Creech, 1792), Vol. 1, 206.

[8] George Turnbull, Philosophical Theses (45-57), 49.

[9] George Turnbull, Observations Upon Liberal Education (London: A. Millar, 1742), 182-183.

[10] George Turnbull, Principles of Moral Philosophy (London: John Noon, 1740), 65-66.

[11] Ibid.,63.

[12] Adam Ferguson, Principles of Moral and Political Science, (Edinburgh: W. Creech, 1792) Vol. 1, 47.

[13] Ibid., 281.

[14] Francis Hutcheson, "On the Natural Sociability of Mankind: Inaugural Oration" in Logic, Metaphysics, and the Natural Sociability of Mankind, ed. James Moore and Michael Silverthorne, (Indianapolis: Liberty Fund, 2006). The Online Library of Liberty

[15] Adam Ferguson, Principles of Moral and Political Science Vol. 1, 194.

[16] George Turnbull, Observations Upon Liberal Education, 194.

[17] Ibid., 56-57.

[18] Ibid.,79.