 Synthesis is carried out by the unitary subject of representation on representations that are either given to it in sensibility (i.e., intuition and/or sensation) or produced by it via the intellect (e.g., in an act of judgment). When synthesis is carried out on representations forming the content of a concept or judgment, it is called “intellectual” synthesis; when carried out by the imagination on material provided by sensibility (i.e., on intuition and sensation), it is called “figurative” synthesis (B150-1). In the Critique of Pure Reason Kant discusses in some depth the synthesis performed on representations provided by sensibility, and discusses three central kinds of synthesis—viz. apprehension, reproduction (or imagination), and recognition (or conceptualization) (A98-110/B159-61). Though Kant discusses these forms of synthesis in a way that suggests they are discrete types of mental acts, it is also plausible that they always go together (Paton 1936: 271–272; Kemp Smith 2003: 245–246), or at least that the first two forms must always occur together, with the third being (perhaps) an optional addition (Brook 1997; Allais 2009).