The natural philosopher, in addition to the sensations common to all men inspired by the event of death, believes that he sees with more certainty that it is attended with the annihilation of sentiment and thought. He observes the mental powers increase and fade with those of the body, and even accommodate themselves to the most transitory changes of our physical nature. Sleep suspends many of the faculties of the vital and intellectual principle; drunkenness and disease will either temporarily or permanently derange them. Madness or idiotcy may utterly extinguish the most excellent and delicate of those powers. In old age the mind gradually withers; and as it grew and was strengthened with the body, so does it together with the body sink into decrepitude. Assuredly these are convincing evidences that so soon as the organs of the body are subjected to the laws of inanimate matter, sensation, and perception, and apprehension, are at an end. It is probable that what we call thought is not an actual being, but no more than the relation between certain parts of that infinitely varied mass, of which the rest of the universe is composed, and which ceases to exist so soon as those parts change their position with regard to each other. Thus colour, and sound, and taste, and odour exist only relatively. But let thought be considered as some peculiar substance, which permeates, and is the cause of, the animation of living beings. Why should that substance be assumed to be something essentially distinct from all others, and exempt from subjection to those laws from which no other substance is exempt? It differs, indeed, from all other substances, as electricity, and light, and magnetism, and the constituent parts of air and earth, severally differ from all others. Each of these is subject to change and to decay, and to conversion into other forms. Yet the difference between light and earth is scarcely greater than that which exists between life, or thought, and fire. The difference between the two former was never alleged as an argument for the eternal permanence of either, in that form under which they first might offer themselves to our notice. Why should the difference between the two latter substances be an argument for the prolongation of the existence of one and not the other, when the existence of both has arrived at their apparent termination? To say that fire exists without manifesting any of the properties of fire, such as light, heat, &c., or that the principle of life exists without consciousness, or memory, or desire, or motive, is to resign, by an awkward distortion of language, the affirmative of the dispute. To say that the principle of life may exist in distribution among various forms, is to assert what cannot be proved to be either true or false, but which, were it true, annihilates all hope of existence after death, in any sense in which that event can belong to the hopes and fears of men. Suppose, however, that the intellectual and vital principle differs in the most marked and essential manner from all other known substances; that they have all some resemblance between themselves which it in no degree participates. In what manner can this concession be made an argument for its imperishability? All that we see or know perishes and is changed. Life and thought differ indeed from everything else. But that it survives that period, beyond which we have no experience of its existence, such distinction and dissimilarity affords no shadow of proof, and nothing but our own desires could have led us to conjecture or imagine.

Have we existed before birth? It is difficult to conceive the possibility of this. There is, in the generative principle of each animal and plant, a power which converts the substances by which it is surrounded into a substance homogeneous with itself. That is, the relation between certain elementary particles of matter undergo a change, and submit to new combinations. For when we use the words principle, power, cause, &c., we mean to express no real being, but only to class under those terms a certain series of coexisting phenomena; but let it be supposed that this principle is a certain substance which escapes the observation of the chemist and anatomist. It certainly may be; though it is sufficiently unphilosophical to allege the possibility of an opinion as a proof of its truth. Does it see, hear, feel, before its combination with those organs on which sensation depends? Does it reason, imagine, apprehend, without those ideas which sensation alone can communicate? If we have not existed before birth; if, at the period when the parts of our nature on which thought and life depend, seem to be woven together, they are woven together; if there are no reasons to suppose that we have existed before that period at which our existence apparently commences, then there are no grounds for supposition that we shall continue to exist after our existence has apparently ceased. So far as thought and life is concerned, the same will take place with regard to us, individually considered, after death, as had place before our birth.

It is said that it is possible that we should continue to exist in some mode totally inconceivable to us at present. This is a most unreasonable presumption. It casts on the adherents of annihilation the burthen