Letters 108.21

therefore, while holding to your own view, keep the whole question in abeyance in your mind. If the theory is true, it is a mark of purity to refrain from eating flesh; if it be false, it is economy. And what harm does it do to you to give such credence? I am merely depriving you of food which sustains lions and vultures.”

Seneca, Letters to Lucilius 108.21, translated by Richard Mott Gummere