The past feelings of the mind, then, are, as it were, objects present to the mind itself, and acquire, thus truly, a sort of relative existence, which enables us to class the phenomena of our own spiritual being as we class the phenomena of the world without. The mind is that which we know to have been susceptible of all the variety of feelings which we remember; and it is only as it is susceptible of all these varieties of feeling, that we can have any knowledge of it. We define it therefore, by stating its various susceptibilities, including more or fewer of these, in our definition, as we may either have observed or remembered more or less, or generalized more or less what we have observed and remembered; precisely as in our definition of matter, we include more or fewer qualities, according to the extent of our previous observation and arrangement. That we know _matter_, only as relative to our own susceptibility of being affected by it, does not lessen the value of the knowledge of it, which we are able to acquire; and, indeed, it is only as it is capable of affecting us, that the knowledge of it can be of any direct and immediate utility. It would, indeed, be the very absurdity of contradiction, to suppose ourselves acquainted with qualities which cannot affect us. But, even though this were possible, how profitless would the knowledge be, compared with the knowledge of the qualities which are capable of affecting us; like the knowledge of the seasons of the planet Saturn, or of the planets that have the Dog Star for their sun, compared with the more important knowledge of the seasons of our own globe, by which we have the comfort of anticipating, in the labours of spring, the abundance of autumn, and gather in autumn the fruits, which, as products of vernal labour, are truly fruits of the spring. To know _matter_, even _relatively_, as our limited senses allow us to know it, is to have knowledge which can scarcely be called limited. Nothing, indeed, can seem more narrow in extent, if we think only of the small number of our senses, by which alone the communication can be carried on. But what infinity of objects has nature presented to each! In the mere forms and colours that strike our eyes, what splendid variety! the proportion of all things that bloom or live, the earth, the ocean, the universe, and almost God himself appearing to our very senses, in the excellence and beauty of the works which He has made!