As a 3-dimensional object, the Tree of Life consists of 16 triangles with 10 vertices and 22 edges. The picture depicts it from above its apex, the broken lines indicating Paths that lie behind other Paths. These three numbers have representation in terms of a square and the integers 1, 2, 3 & 4. Such representations are examples of a 'Tetrad Principle' governing holistic systems. This determines parameters of universal (and therefore scientific) significance as either various numbers characterising or belonging to the fourth member of a class of mathematical object (which may, itself, be a type of number) or as the sum of the first four members of a class of numbers. The principle is demonstrated par excellence in the tetractys itself, which symbolizes the number 10 as the sum of the first four integers. This makes it the fourth, so-called 'triangular number' (triangular numbers are those numbers that can be represented by triangular arrays of the number 1, the nth triangular number being a triangular array with n 1's along each side).