  contains further discussion.) The easiest way to get a grip on this is to think of senses as purely qualitative satisfaction conditions. Such a condition determines an object in virtue of the qualities it instantiates. According to Russellianism, on the other hand, we can think about an individual directly; we can have a thought about an individual by having that individual as an immediate constituent of the thought. On the standard interpretation of Frege, individuals are not constituents of propositions. Propositions are composed of senses, not individuals, and senses are individuated independently of any individual. If Fregeanism is true, there are no singular propositions. If Russellianism is true, then singular propositions play a crucial role in semantics and any complete theory of  thought.