We examine copy raising in two closely related Germanic languages, English and Swedish, and offer a formal analysis of its syntax and semantics. We concentrate particularly on the latter aspect and develop a new event semantics analysis of copy raising. In addition to augmenting the body of empirical data on copy raising, we show that far from being a marginal or theoretically uninteresting phenomenon, copy raising yields novel insights into a number of key theoretical issues, in particular language and perception, the theory of arguments and thematic roles, and the broader semantics of control and raising. Copy raising casts new light on the linguistic encoding of perceptual reports. We investigate in detail the source of perception, which can be thought of as the stimulus in a perceptual event or state, and briefly examine the goal of perception, i.e. the perceiver. Our analysis of perceptual sources in copy raising in turn has consequences for the distinction between arguments/thematic roles and other participants in events and states. In particular, we argue that perceptual sources and goals are not linguistically encoded as semantic arguments. We examine the consequences of the semantics of copy raising, and raising more generally, and of perceptual sources and goals in particular, for theories of thematic roles. We argue that certain finer grained distinctions must be introduced to linguistic theory to properly deal with the semantics of raising and copy raising. We demonstrate how our semantics for copy raising connects to the semantics of both control and standard raising. Copy raising and related perceptual constructions reveal a richer semantic space for control and raising than has hitherto been explored. Along the way, we observe and solve two empirical puzzles. The first concerns a contrast that holds in both Swedish and English between copy raising and subject-to-subject raising in certain contexts. The second concerns the distribution of an adjunct that encodes the source of perception in Swedish.