We see that God has implanted in all things a natural desire to exist with the fullest measure of existence that is compatible with their particular nature. To this end they are endowed with suitable faculties and activities; and by means of these there is in them a discernment that is natural and in keeping with the purpose of their knowledge, which ensures their natural inclination serving its purpose and being able to reach its fulfilment in that object towards which it is attracted by the weight of its own nature.