5 The sinister deities preside over the regions on the left hand only, and are opposed to those on the right. But with what reason this is said, or with what meaning, we do not understand ourselves; and we are sure that you cannot in any degree cause it to be clearly and generally understood. For in the first place, indeed, the world itself has in itself neither right nor left neither upper nor under regions, neither fore nor after parts. For whatever is round, and bounded on every side by the circumference of a solid sphere, has no beginning, no end; where there is no end and beginning, no part can have its own name and form the beginning.
Therefore, when we say, This is the right, and that the left side, we do not refer to anything in the world, which is everywhere very much the same, but to our own place and position, we being so formed that we speak of some things as on our right hand, of others as on our left; and yet these very things which we name left, and the others which we name right, have in us no continuance, no fixedness, but take their forms from our sides, just as chance, and the accident of the moment, may have placed us.
If I look towards the rising sun, the north pole and the north are on my left hand; and if I turn my face there, the west will be on my left, for it will be regarded as behind the sun's back. But, again, if I turn my eyes to the region of the west, the wind and country of the south are now said to be on my left. And if I am turned to this side by the necessary business of the moment, the result is, that the east is said to be on the left, owing to a further change of position, — from which it can be very easily seen that nothing is either on our right or on our left by nature, but from position, time, and according as our bodily position with regard to surrounding objects has been taken up.
But in this case, by what means, in what way, will there be gods of the regions of the left, when it is clear that the same regions are at one time on the right, at another on the left? Or what have the regions of the right done to the immortal gods, to deserve that they should be without any to care for them, while they have ordained that these should be fortunate, and ever accompanied by lucky omens?
Source: Against the Heathen (New Advent)