IF that which exists be not such as we can conceive in our thoughts, how is it to be known? or at least how can the intellect have any part in the attainment of a knowledge in the possession of which it cannot participate?

The answer to this question is simple. The intellect is a means towards acquiring knowledge in the same way that the senses are. Not a ruler, but a servant. Our necessary conceptions, or thoughts, are not correspondent with the absolute truth of things, but they are elements from which that truth may be gathered. They are materials to be used. Even so the impressions we derive from sense do not correspond to the relative truth of things, or to the right conception of them; yet are they the means by which we ascertain that relative truth. The intellect contributes to a knowledge not intellectual, as the sense contributes to a knowledge not sensuous. We learn from our senses, by examining, and ascertaining the conditions which cause them to be affected as they are. We learn from our intellect, by examination likewise, and by ascertaining what the circumstances are that necessitate our having the conceptions we are obliged to form.

When the distinction is borne in mind between that which it is necessary for us to infer and that which is true, the part which the intellectual operations bear in human history is evident. Our thoughts and conceptions are to be interpreted by a knowledge of ourselves and of our relations.