I`ve started to read on FOM, and unfortunately I found the first paragraph cumbersome to get. Here is the text I started with: http://www.math.psu.edu/simpson/hierarchy.html [Broken] The first paragraph was: "1. All human knowledge is conceptual and forms an integrated whole. All human knowledge is contextual and hierarchical." The three radical words are: conceptual, contextual, and hierarchical. I understand what "hierarchical" means. I`m gonna get back to "contextual" later. Now what I`d like to understand is the word "conceptual", so can I get help here? I did some researching about "conceptual", and one good website was: http://www.education.com/reference/article/distinction-conceptual-procedural-math/ But no single website gave a precise definition of what "conceptual" means.. which makes me scratch my head really hard trying to understand based on what did the author of the FOM text use the word "All" at the beginning of the text, and what was he thinking of when he used the word "conceptual".