Summary: Critique of Pure Reason (page 4)

This is significant because, until then, metaphysics had been regarded—at least within the Scholastic tradition—as the queen of the sciences. The superiority of its subject matter (God, etc.) led to the belief in the superiority of its results.

With Kant, however, metaphysics is expelled from the domain of knowledge altogether and no longer qualifies as a science in any sense—a position that would be adopted by all modern thinkers. Its objects (God, immortality, etc.) are relegated to the realm of belief and theology.

We are now in a position to understand the title of the work. This requires grasping another Kantian distinction: that between the understanding, which merely analyses the data of experience, and Reason, the higher faculty of the mind that naturally rises above experience and forges Ideas (such as God), which it then mistakenly takes as objects of knowledge.

As we have seen, pure refers to the notion of a priori. A metaphysical system, in fact, consists of a set of a priori (or pure) judgements, since they cannot be grounded in experience.

Pure reason, then, is that power of the mind which leads us to have metaphysical thoughts.

The task is to undertake its critique—that is, to demonstrate that this faculty of the mind cannot constitute true knowledge.

We can now better understand what Kant means by Critique of Pure Reason. The title of the work is now fully explained.

Let us now begin our reading of the first Preface and explore a text that should now appear clearer to us.

Kant begins by describing the misfortune of reason: its tendency to ask metaphysical questions that can never be resolved, as they exceed the limits of human reason, since they go beyond any possible empirical use¹.

For example: Does God exist? But also: Is there a first cause, or does the chain of causes and effects extend infinitely? Are we free? and so on.

These questions are insoluble, yet this does not stop the mind from asking them. On the contrary, it leads to endless conflicts—the battles of metaphysical systems (those of Plato, Leibniz, Spinoza, etc.):

The battlefield upon which these ceaseless conflicts unfold is called Metaphysics.

These systems were dogmatic, as they could not prove the truth of the first principles upon which they were based. As a result, scepticism developed—not only against these systems but also against the very possibility of knowledge itself.

Yet, one cannot simply remain indifferent to these metaphysical questions. It matters to everyone to know whether they are truly free or whether there is life after death, for example.

It is therefore necessary to establish a tribunal that can, as we have seen, guarantee reason in its legitimate claims, while at the same time rejecting its unfounded pretensions. In other words, to identify which propositions belong to well-founded knowledge and which belong to mere belief.

This is the origin of Kant’s project: this tribunal is none other than the Critique of Pure Reason.

This is, by nature, a humble project, as it seeks to identify the limits of reason. It stands in opposition to the pretensions of dogmatism—the pride of the metaphysician, who claims to extend human knowledge beyond all possible limits of experience, asserting, for instance, the demonstrable simplicity of the soul or the necessity of a first beginning of the world.

The central question of the work, let us recall, remains the following:

What can the understanding and reason know, and to what extent can they know, independently of all experience?

Here, we must recognise that the mind is about to take itself as its own object of study. The understanding will examine the way it functions. Yet, this is precisely what will guarantee the certainty of the results obtained.

Indeed, if reason examines itself, then in order to attain a detailed knowledge of it, I need not search far and wide, since I encounter it within myself.

Or, to put it differently: Nothing here can escape us, for what reason produces entirely from within itself cannot remain hidden.

¹ Our translation. The references for the quotations are available in the book Kant: A Close Reading