Philosophy and Common Sense
Before we know things with a scientific knowledge by reflecting upon them and by investigating into their causes, we know with unscientific knowledge – the knowledge of everyday life. We are obliged not only to begin with this unscientific knowledge of everyday life; we must be content with it to the end, improving it more or less by study and reading.
For no man can specialise in all branches of science. He is fortunate, indeed, if he can make himself master of a single science. For all the others he must be satisfied with the knowledge of a cultivated man.
But in the domain of first causes -the science of all things- is within a man’s grasp to know all things and in this way become universal.
Ordinary knowledge consists for the most part of mere opinions or beliefs, more or less well founded. But it implies a solid kernel of genuine certainties in which the philosopher recognises:
- data of the senses (for example, that bodies possess length, breadth, and height),
- Self-evident axioms (for example, the whole is greater than the part, every event has a cause, etc.),
- Consequences immediately deducible from these axioms (proximate conclusions).
These certainties which arise spontaneously in the mind when we first come to the use of reason are thus the work of nature in us, and may therefore be called an endowment of nature, for it proceeds from the natural perception, consent, instinct, or natural sense of the intellect.
Since their source is human nature itself, they will be found in all men alike; in other words, they are common to all men. They may therefore be said to belong to the common perception, consent, or instinct, or to the common sense of mankind.
The great truths without which man’s moral life is impossible – for example, knowledge of’ God’s existence, the freedom of the will, etc. – belong to this domain of common sense, as consequences immediately deducible (proximate conclusions) from primary data apprehended by observation and first principles apprehended by the intellect.
All men, unless spoiled by a faulty education or by some intellectual vice, possess a natural certainty of these truths. But those whose understanding has never been cultivated cannot explain why they possess them.
These certainties of common sense, conclusions of an implicit reasoning, are as well the foundation of science.
But their possessor has no knowledge, or an imperfect knowledge, of the grounds on which he bases them. They are therefore imperfect not in their value as truth but in the mode or condition under which they exist in the mind.
Common sense possesses also a knowledge of the self-evident truths (the whole is greater than the part, – every event has a cause, etc.). These self-evident truths are the object of what is termed the understanding of principles whoich certainty is superior to that of any conclusion of science.
Although it is a knowledge equally imperfect because it is confused and implicit. Common sense therefore may be regarded as the natural and primitive judgment of human reason:
– but imperfect in its mode.
The wholly spontaneous character of common sense, and its inability to give an account of its convictions, have led certain philosophers to regard it:
- As a special faculty purely instinctive and unrelated to the intellect
- Or as a sentiment distinct from and superior to reason (the intuitive or sentimentalist school; for instance, Rousseau, and Bergson).
But in that case it would necessarily be blind, for we possess no other light than that of the intellect or reason. The light of common sense is fundamentally the same light as that of science, that is to say, the natural light of the intellect. But in common sense this light does not return upon itself by critical reflection, and is not perfected by a scientific habit.
Relations between philosophy and common sense
Philosophy cannot, as the Scottish school maintained, be founded on the authority of common sense understood simply:
- As the common consent or universal witness of mankind,
- Or as an instinct which in fact compels our assent.
- For it is in fact founded on evidence, not on authority of any kind.
But if by common sense we understand only the immediate apprehension of self-evident firs principles, which is one of its constituents, we may say with truth that it is the source of the whole of philosophy.
For the premisses of philosophy are indeed the evident axioms which in virtue of its natural constitution implant in the mind its primary certainties. It is important to be quite clear that, if philosophy finds its premisses already enunciated by common sense, it accepts them: not because they are enunciated by common sense, or on the authority of common sense understood as the universal consent or common instinct of mankind, but entirely and solely on the authority of the evidence.
Finally, if we take into account the entire body of truths (premisses and conclusions) known by common sense with certainty but in an imperfect mode, we must conclude: that philosophy is superior to common sense, as the perfect stage of anything is superior to the imperfect stage of the same thing which is yet true and certain at both stages).
If in common sense we consider:
not the conclusions which it reaches but the premisses alone, it is still inferior to philosophy in respect of its mode of knowledge, but equal to philosophy and to all the sciences in respect of its object and of the light in which it knows.
For, as we have said above, philosophy and all the sciences are ultimately founded on the natural evidence of first principles to which philosophy returns -in criticism- to study them scientifically, whereas the other sciences are content lo accept them from nature.
Philosophy studies scientifically the three categories of truths to which common sense bears instructive witness:
- the truths of fact which represent the evidence of the senses;
- the self-evident first principles of the understanding, in as much as it clears up their meaning by critical reflection and defends them rationally;
- the consequences immediately deducible (proximate conclusions) from these first principles, inasmuch as it provides a rational proof of them.
Where common sense yields to the mere opinion of popular beliefs, philosophy tries to establish the scientific certainty of these beliefs.
It is also the province of philosophy to decide what are the genuine certainties affirmed by common sense, and what is their true significance; a function which common sense is incapable of performing, because it does not understand clearly, the grounds of its knowledge.
In this sense philosophy controls common sense
Nevertheless common sense has the right and duty to reject any philosophic teaching which denies a truth of which it possesses natural certainty (as the inferior has the right and duty to oppose a superior who acts in a manner evidently unjust).
For as soon as a truth becomes known to us, by whatever channel, it is a sin not to accept it. Common sense may therefore accidentally judge philosophy.
It is related of Diogenes that when Zeno the Eleatic was arguing in his presence against the possibility of motion, his sole reply was to get up and walk.
Similarly, when Descartes taught that motion is relative or “reciprocal,” so that it makes no difference whether you say the moving object is moving towards the goal or the goal towards the moving object, the English philosopher Henry More retorted that when a man runs towards a goal panting and tiring himself, he has no doubt which of the two, the moving object or the goal, is in motion.
These protests of common sense based on the evidence of the senses were perfectly justified. It must, however, be added that they were insufficient, not indeed to confute the respective theses of Zeno and Descartes, but to confute them as errors in philosophy.
That would have demanded a philosophic refutation of the arguments adduced by these philosophers, and explanations showing why and at what point they went wrong.
It is now evident how unreasonable that philosophy is, which prides itself on its scientific knowledge of things:
– despising common sense a priori and on principle,
– and cuts itself off from its natural convictions.
Descartes began this divorce by admitting as the only certain truths those scientifically established, thus denying the intrinsic value of the convictions of’ common sense.
Certain modernist philosophers have carried this tendency to its extreme looking as suspicious any truth based upon the evidence of common sense.
Thomism keeps the balance between these two opposing errors like.
|Philosophy of Aristotle and Sr. Thomas||Scottish School||Rationalist, Critical, and Modernist Schools|
|The convictions of common sense are valid, and science is untrue lo itself if it rejects them. But the basis of philosophy is the natural witness of the intellect, not the authority of common sense.||Not only are the convictions of common sense valid, bat the authority of common sense imposing itself as a blind instinct on the mind is the foundation on which philosophy should be based.||Not only is the authority of common sense incapable of furnishing the basis of philosophy, but the convictions of common sense are destitute of any speculative value.|
From all that has been said it is evident what an important part the certainties of common sense play as an introduction to philosophy. Those who are beginning the study of philosophy and about to acquaint themselves:
- with the most recent problems,
- and even perhaps the most misleading systems,
ought to repose an absolute trust in the convictions of common sense of which they find their minds already possessed. For they will help them to rise to a higher and more perfect knowledge, conclusions scientifically established.