The Author of the Plurality of Worlds [1] draws a very good Argument from this Consideration, for the peopling of every Planet; as indeed it seems very probable from the Analogy of Reason, that if no Part of Matter, which we are acquainted with, lies waste and useless, those great Bodies which are at such a Distance from us should not be desart and unpeopled, but rather that they should be furnished with Beings adapted to their respective Situations.

Existence is a Blessing to those Beings only which are endowed with Perception, and is in a manner thrown away upon dead Matter, any further than as it is subservient to Beings which are conscious of their Existence.  Accordingly we find, from the Bodies which lie under our Observation, that Matter is only made as the Basis and Support of Animals, and that there is no more of the one, than what is necessary for the Existence of the other.

Infinite Goodness is of so communicative a nature, that it seems to delight in the conferring of Existence upon every Degree of [Perceptive [2]] Being.  As this is a Speculation, which I have often pursued with great Pleasure to my self, I shall enlarge farther upon it, by considering that part of the Scale of Beings which comes within our Knowledge.

There are some living Creatures which are raised but just above dead Matter.  To mention only that Species of Shell-fish, which are form’d in the Fashion of a Cone, that grow to the Surface of several Rocks, and immediately die upon their being sever’d from the Place where they grow.  There are many other Creatures but one Remove from these, which have no other Sense besides that of Feeling and Taste.  Others have still an additional one of Hearing; others of Smell, and others of Sight.  It is wonderful to observe, by what a gradual Progress the World of Life advances through a prodigious Variety of Species, before a Creature is form’d that is compleat in all its Senses; and even among these there is such a different Degree of Perfection in the Sense which one Animal enjoys beyond what appears in another, that though the Sense in different Animals be distinguished by the same common Denomination, it seems almost of a different Nature.  If after this we look into the several inward Perfections of Cunning and Sagacity, or what we generally call Instinct, we find them rising after the same Manner, imperceptibly one above another, and receiving additional Improvements, according to the Species in which they are implanted.  This Progress in Nature is so very gradual, that the most perfect of an inferior Species comes very near to the most imperfect of that which is immediately above it.