 The philosophy of naturalism holds that all that exists in the universe, all that exists at all, is physical existence that science studies. There isn't a separate realm of mental events, there isn't a separate realm of mathematics. There is just natural stuff in nature that science describes. If you believe that, you're a naturalist. However, there's a big division within naturalism depending on your view of the nature of time. And I'm going to talk about naturalism, version one, or what might be called timeless naturalism, which is the presently dominant view. It is the view that Einstein was refining from that quote. It is the view in which time either disappears or is just another dimension. In any case, there's no objective reality to our experience of the present moment within naturalism, version one. So let's talk about naturalism, version one, and then I will explain what's wrong with it. And then I will introduce you to naturalism, version two, which is intended to be a cure for the problems that arise in naturalism, version one. So is anybody with me? Okay. Naturalism version one started also with the Greeks, with the Atomists, by the conception that nature is nothing but atoms moving in the void. All sensory experiences we have, all sensations, all colors, all sounds, all hardness, all softness, all texture is all just a reflection of different ways that the atoms can be arranged and moved. In other words, atoms, which are according to Democritus and Lucretius, eternal and unchanging, the properties of the atoms don't change. Just like the properties on the list of the elementary particles of the standard model don't change in time. The charges in the different gauge groups of the quarks and the electron and the metronome sort of don't change in time. We assume that the elementary particles have unchanging properties. They move according to laws which are unchanging in a space or a void which is also unchanging. That's had to be updated a little bit with general relativity, but that actually can be incorporated in the philosophy. This is the picture, atoms moving in a void, that all else is secondary, is emergent as we would say, secondary as John Monopoli said, emergent as we would say in the present era. Everything that's not the motion or the position of an atom or a collection of atoms is emergent, is a property which is not essential to the fundamental description of nature, but only emerges from collective properties and materials or atoms at a large scale. This is the philosophy that I think we all believe in, and I'm not going to be challenging its essential aspects, but I will be challenging it on one point, which is the relationship to the notion of time as we see. And to say it very simply, if the laws are timeless, if the laws are not the result of some process of dynamics and process of causation, they're inexplicable within the methods that we physicists have to bring to science. Because we can explain why this is the way it is, we can answer why something is the way it is, when it's the result of some cause or process that's evolved in time. The presumption that the laws of nature are timeless are not phenomena that are influenceable or evolvable. It means that they're outside of explanation. They're inexplicable. And that's the crisis of physics that we face.