WikiMechanics

According to the ontological theory of bundles developed in the 18th century by Scottish philosopher David Hume, an object consists of its properties and nothing more. This agrees with the first meaning given for object in a popular dictionary; "anything that is or may be apprehended by the senses; especially a tangible or visible thing".¹ But according to substance theory, an object is more than just its sensory properties. This point of view becomes relevant in discussions about free will, liberty, the value of human life and other very important concerns.

For WikiMechanics let us take Hume's position, at least as a definition for physical objects, but with the constraint that we should be cautious in consideration of human bodies. This is partly to avoid bundle versus substance disputes, but also because our reference sensations are humanistic and we want to avoid getting into illogical circular reasoning. This proviso limits the range of validity of WikiMechanics. Accordingly we define a physical object as anything that may be perceived by the senses, especially a tangible or visible thing. Discrete physical objects are often called particles. This definition applies to all the sensations we use to describe events. So every event, large or small, can also be thought of as a particle. But changing back and forth between events and particles can get very confusing. So usually we reserve the word event for specific sensations that we note using the symbol P_k. Later as we gloss over sensual detail, the word particle and symbol P prevail.