Full Idea
Relations in intension are of the utmost importance to philosophy and philosophical logic, since they are essential to complexity, and thence to propositions, and thence to the possibility of truth and falsehood.
Clarification
'in tension' means (here) in the mind
Gist of Idea
There is no complexity without relations, so no propositions, and no truth
Source
Bertrand Russell (Substitutional Classes and Relations [1906], p.174)
Book Reference
Russell,Bertrand: 'Essays in Analysis', ed/tr. Lackey,Douglas [George Braziller 1973], p.174
A Reaction
Should we able to specify the whole of reality, if we have available to us objects, properties and relations? There remains indeterminate 'stuff', when it does not compose objects. There are relations between pure ideas.