Our present-day knowledge prompts the adoption of a middle course between the two theories.
In his view, Nature has made provision for social wellbeing by the principle of the human constitution which prompts every man to better his condition: the individual aims only at his private gain, but is "led by an invisible hand" to promote the public good; human institutions, by interfering with this principle in the name of the public interest, defeat their own end; but, when all systems of preference or restraint are taken away, "the obvious and simple system of natural liberty establishes itself of its own accord."
It may be affection, or it may be fear, which prompts the survivor to feed and tend his dead; in general no doubt it is a mixture of both feelings.
ALASTOR, in Greek mythology, the spirit of revenge, which prompts the members of a family to commit fresh crimes to obtain satisfaction.
In man, as in every other animal, from the moment of birth natural impulse prompts to the maintenance of his physical frame; then, when reason has been developed and has recognized itself as its own sole good, these " primary ends of nature " and whatever promotes these still constitute the outward objects at which reason is to aim; there is a certain value (a La) in them, in proportion to which they are " preferred " (7rponyµtva) and their opposites " rejected " (ci roirpony,ubm); indeed it is only in the due and consistent exercise of such choice that wisdom can find its practical manifestation.