Quote from Lee Smolin in Scientific American:
There are some lazy ideas about unification that reflect uncritical thinking, such as the idea that the more fundamental a phenomena [sic] is the more symmetry it must have. When you think seriously about the problem you realize it must be exactly the opposite. Roger Penrose use to say this, and indeed the insight that the most fundamental theory can have no symmetries goes back to Leibniz.
Also does anyone know what exactly Leibniz had to say on the matter?
Lee Smolin doesn’t mean that the most fundamental physical theory can have no symmetry. What he means is that symmetry shouldn’t be the guiding principle in discerning fundamental physical theories. While symmetry is mathematically useful, it doesn’t provide a sufficient reason to accept a theory, this goes back to Leibniz’s principle of sufficient reason. Smolin wants physicists to abandon trying to find timeless laws and symmetries, and like biology understand how laws evolve; he advocates a theory of cosmological evolution. Note: I don’t agree or disagree with Smolin, I am just stating what he believes.
This blog site should help you. Here, Leibniz’s other principles of network relations, indiscernibles, etc. are used to explain Smolin’s argument.