I do not think so meanly of Allegorical representations as you seem to imagine; though I have not much taste for them, or satisfaction in them, which may be a defect of genius in me, for the greatest men of antiquity have dealt much in them; and, indeed, could they be distinct enough, and universally acknowledged and received (which seems to have been the original intention of them) nothing could more deserve cultivation, as being (so circumstanced) an "universal language;" and, so far as any of them have the above characteristics, really are so. And Rubens is said to have been very learned herein, and to have used none but authorized symbols, &c. and those with great justness and propriety.
One thing that has disgusted me amongst others is, that the same symbols are often given to different characters, and at other times different symbols to the same characters, so as to leave uncertainty and confusion in the mind of the spectator, or reader. See, for instance, the Nine Muses in the books ... and again in the Polymetis of Spence, who intends to distinguish them; but whether it is the fault of these writers, or, indeed, the real confusion in the ancient statues, or bas-reliefs, or however it happens, I never yet saw them so distinguished as to know them any one from every other of them; but without, there may be as well nineteen as nine; or only three, or any other number. I cannot help adding, that, if the symbolical figures of the ancients really are distinct, then they should be considered and treated as a sacred text, and it should be deemed a kind of sacrilege to innovate with respect to those left by them; but, if they are transmitted to us in such confusion as above represented, they deserve but little regard.