An inordinate tendency to generalise is so far from being a feature of a philosophic mind, that it is rather an indication of weakness of intellect. No definition can be just which is not the result of patient induction ; and in those cases, in which the variations are so numer ous, that it is scarcely practicable to reduce them to any general heads, it is much wiser to abstain from attempt ing to define, than to hazard a definition, which the dis covery of a new fact may effectually overturn. To trace the distinctions between plants and animals, would be to write the history of all the genera and species com prehended under these great classes; for, where the number of objects is incalculable, and the variations endless, it is next to impossible to decide what are the most general qualities.
After all, it must be owned, that sensation is the best distinctive mark, which, in the present state of natural knowledge, we can possibly adopt, as it forms the boun dary between animals and vegetables. The appearances, resembling sensation in some genera of plants, bear a much stronger analogy to irritability; and, indeed, we can discover no end which could be served by bestowing sensitive powers on plants. It is only reverting to the ideas of savages, to attempt to people nature with ani mated beings, and to dignify the humblest varieties of organic matter with vitality and intelligence, with voli tion and affection, or, at least, with capacities of enjoy ment which imply choice and desire, and a sense of the adaptation of means to ends.
That plants are not furnished with any means of self Veservation cannot be denied ; and as they are so con stantly exposed to mutilation or destruction, by the vora city of animals, it has been very plausibly maintained, that it is not likely that the benevolent Author of nature would endow them with a sensitive capacity, which must subject them to perpetual torture. This argument,
however, though specious, is not decisive. It is possi ble that plants may have sensations which yield them pleasure, and that they may, notwithstanding, expe rience no greater degree of pain, from the ravages com mitted on them by the animal creation, than many of the insects, and reptiles, and fishes, which arc daily de voured by their stronger fellow creatures. Nay, it is possible, that the destruction of plants may be no more painful than what takes place on our own bodies, which furnish nourishment to various orders of creatures which prey on our substance, and partake of our aliment, with out (in ordinary cases,) producing any sensible molesta tion. But though all this be possible, it is not probable ; and yet there are some fanciful speculatists who insist, that the vast spaces occupied by plants, in the bottom of the deep, and on the elevated solitudes, covered by per petual snow, and untrodden by the beasts of the field, or the fowls of the air, or any creeping thing, cannot be destitute of _animation, and that this animation resides in these vegetables themselves. With equal reason we may pronounce the snows themselves to be endowed with vitality. If this be philosophy, we may boldly affirm, that the stupendous masses of rocks, rising from the summit of the steep, unclothed with verdure, and unvisited by any living thing, are a gigantfc people threatening the heavens, and that the unmeasured sands