Physical, Design, Intentional: An elaboration on "algorithm". In a previous thread (with which I'm going to try to catch up soon), I basically stated that all that must be explained, outside of the purely physical (synaptic) behaviors, was the algorithms governing them. I should have been more specific, as Dennett has been, since there are actually three stages of existence in Dennettian Materialism, though they can all be reduced to the physical (which is what makes it Materialism). Note: I am using the term "physical" with regard to the material and the behavior thereof. I am of the (current) opinion that everything is actually "physical", but I'm shortening the range of that word for the purpose of this discussion. The first stage, according to Dennett, is the "Physical". The Physical is the level at which one finds particles and their behavior. It is the level, logically, of physicists. The second stage/level, is the "Design stage". This (along with the next stage) is part of what I refer to by "algorithm" in the aforementioned thread. The Design level is the level at which, for example, a piece of music exists. The piece Ein Klein Nachtmusik (by Mozart) exists, regardless of whether it is written on a piece of paper, played by an orchestra, played by a solo piano, or played by some recording. Now, since Ein Klein Nachtmusik is an algorithmic (using the term loosely) construct of whatever physical medium on which it represents itself, it remains reducibly physical, even though it itself cannot be reduced in any meaningful way (since it is independent of its medium...i.e. one could reduce any of it's manifestations, but reference to it itself doesn't make much sense if it is only taken in part). Dennett has sometimes referred to the Design level as the "level of software", from which numerous other examples could be taken. Finally, the Intentional stage is the level at which a process appears to have a will of its own. It appears to be "trying" to do something. The Intentional level is to the Design level as the Design level is to the Physical level: an algorithmic construct of many discreet units and their behaviors. So, consciousness, which exists at the Intentional level, is an algorithmic construct of algorithmic constructs, which is what makes it so difficult to reduce, in any meaningful sense. However, if one reduces the processes occuring at the Intentional level to the constituent Design processes (which is basically what Hume was doing in separating experience into "ideas (simple and complex)" and "impressions"), and then separate those Design processes (which, btw, include all of the things that Hypnagogue has referred to as "A-consciousness" in the aforementioned thread) into their constituent Physical processes (which is what most scientists, who study the brain, attempt to do), you will have a reductive explanation of consciousness, though there will probably always appear to be something "missing". That "something" would simply be those properties of the higher algorithms which are properties solely of the algorithm (i.e. solely of the many parts, working together) and not of the constituents thereof.