Reason, nature and the human being in the West: Part 2

2.4 Modern Reason

One of the most influential works of the period addressing the nature of 'reason' and its place in the context of human mentality in general was the Essay Concerning Human Understanding (1690) by John Locke.

Locke says reason is a 'faculty':

"[reason as it is understood here] stands for a faculty in man, that faculty whereby man is supposed to be distinguished from beasts, and wherein it is evident he much surpasses them."
Locke, Essay, Bk 4, ch. xvii, section 1.

The view of reason which Locke is articulating has to be understood in the context of the complete picture he had of the mind.

Building on the innovation of Descartes, Locke applied to the mind the atomistic thought that was being applied to the physical world by virtuosi like his friend the chemist Robert Boyle.

Atomism of this kind (it was called 'corpuscularianism') was the orthodoxy as far as the physical world was concerned at the beginning of the 18th Century (remember our earlier discussion). The atoms of the mind were ideas, as Locke drew the picture.

They were inert, like physical atoms.
They came from one of just two sources:
- the senses, Eg The idea yellow came from the sense of sight. or
- reflection. Eg The idea 'calculating' came from reflection, the mind looking at its own operations.

What is there to the mind besides ideas?

There is something which

performs operations on the ideas. And there is something that
'sees' the ideas.

Locke is not very explicit about this awkward feature of the picture of the mind he is espousing. You could caricature his account by saying that inside a person is a mind, and inside the mind, 'seeing' the ideas and operating upon them, is - a smaller person.

Notice incidentally that this picture privileges sight. Ideas are 'seen' by the 'inner eye'. Ideas of all modalities are converted into objects of the quasi-sight of the inner eye.

There are three faculties, according to Locke's analysis.

One is the faculty of sense, whereby we get ideas coming to us from outside.
A second is the faculty of 'inward perception'. By this we get ideas from introspecting the various operations that our ideas are subjected to. For example the idea of calculating.
Reason is the third faculty.

Reason operates in two ways. These two ways reflect the distinction Locke makes between knowledge and opinion.

Where you have a chain of propositions on the model of a geometrical proof, you have a conclusion of which you can be certain. But often our conclusions are not like that. They are supported by evidence, or considerations, but not by strict demonstration. Those conclusions belong to 'probable opinions'. They are probably true, but we cannot be certain about them.

Let me explain a little:

Demonstration

Some knowledge (it is usually assumed) you can get through direct sense experience. When we see an object in front of us, we can be certain it is there. Reason is not involved here.

But (again, this is the familiar account) much of our knowledge is got not directly but by a process of 'deduction'. Locke says that in a deduction, a person (or perhaps the little homunculus who stands looking at the ideas in the mind) start with one idea and end up with another, by following a chain of intermediate ideas which are 'linked' in some way. It is reason which assesses the character of these links.

If the links between each pair of ideas in a chain amount to one idea 'agreeing with' another, you have demonstration. Geometrical proofs are of this kind, and the last item in such a chain of agreeing ideas is something you can be certain of.

First, then, reason tells us the connection there is between successive steps in a demonstration.

Degree of Probability

There is another kind of chain however, where there are links between ideas, but they are not 'agreements'. Locke calls them 'probable connexions'. A chain of ideas linked by 'probable connexions' has as its final idea something that is probably true: but lacking in certainty. Reason's role in this case is to assess the degree of probability in each of the 'connexions', and synthesises those degrees of probablity into an assessment of the probabiity of the concluding idea.

Locke writes:

"For as reason perceives the necessary and indubitable connexion of all the ideas or proofs one to another, in each step of any demonstration that produces knowledge: so it likewise perceives the probable connexion of all the ideas or proofs one to another, in every step of a discourse to which it will think assent due."
John LockeAn Essay Concerning Human Understanding Bk IV, Ch. XVII, Section 2.)

Locke's Essay is available here.

Examples of 'agreement' and 'disagreement':

"For when we know that white is not black, what do we else but perceive, that these two ideas do not agree? When we possess ourselves with the utmost security of the demonstration, that the three angles of a triangle are equal to two right ones, what do we more but perceive, that equality to two right ones does necessarily agree to, and is inseparable from, the three angles of a triangle?"
Locke, An Essay concerning human Understanding Bk IV, Ch. I, Section 2.)

(Leibniz has "identity" in place of "agreement". In proving a conclusion you showed that it contained components that were identical to components present in the premises.)

Notice that the paradigm of reasoning' which is being applied generally in the Modern framework of concepts is mathematical reasoning. Reason within mathematics is the power to establish conclusions from premises.

HUME'S EXPLORATION OF REASON

But this conception of "Reason" made for difficulties, which David Hume, writing later, famously brought out. If Reason was what took you from premises to conclusion, it could play no part in establishing premises. Of course, the premises of one argument might be provable as the conclusion in some more basic argument. But then this more basic argument would be based on premises - premises which could either be derived from some even more basic premises, or stand without benefit of Reason.

It was this conception that lead Hume to doubt the sufficiency of reason to issue in any kind of action:

"... reason is perfectly inert, and can never either prevent or produce any action or affection" (David Hume, A Treatise of Human Nature (1739-40), Bk 1 pt i (i); Vol 2 of Everyman edition, p.167.).

To establish anything, reason had to be given premises, and this conception of it didn't allow for it to play any part in providing the premises - unless they were derivable from more basic posits.

In the field of morals, Hume supposed the premises upon which reason might operate were given by the Passions. Reason could tell us what to do if we wanted to achieve some goal, taking account of whatever facts were available to us: but it couldn't tell us anything on its own.

(Cudworth and Clark had argued that reason, of the same kind that operated in mathematics, was applicable in morals, and allowed us to deduce from the nature of things, with certainty, what we ought to do. Locke agreed insofar as determining moral principles for him was a matter of checking agreements and disagreements among certain of our ideas - the function of our Reason.)

Incidentally, Hume saw clearly that we have got just as much reason to attribute reasoning to the 'brutes' as we have to our fellow human beings.

What do you think?

What is our understanding of reason today? Does it give us (eg via mathematics) access to what is real independently of our senses?

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