Philo Judaeus Quod Deterius Potiori Insidiari Soleat 32

Now I think that it has already been sufficiently shown, that the field to which Cain invites Abel to come, is a symbol of strife and contention. And we must now proceed to raise the question what the matters are concerning which, when they have arrived in the plain, they are about to institute an investigation. It is surely plain that they are opposite and rival opinions: for Abel, who refers everything to God, is the God-loving opinion; and Cain, who refers everything to himself (for his name, being interpreted, means acquisition), is the self-loving opinion. And men are self-loving when, having stripped and gone into the arena with those who honour virtue, they never cease struggling against them with every kind of weapon, till they compel them to succumb, or else utterly destroy them;