Letters 113.10

Then how can you infer that Justice is a living thing? “Justice,” people reply, “is active and helpful; that which acts and is helpful, possesses impulse; and that which possesses impulse is a living thing.” True, if the impulse is its own; (but in the case of justice it is not its own;) the impulse comes from the soul.

Seneca, Letters to Lucilius 113.10, translated by Richard Mott Gummere