 Phenomenal intentionality has been discussed under that label only recently (see, e.g., Horgan and Tienson 2002 and Loar 2003, and related influential work by Searle, Siewert, and others), but many modern philosophers have suggested a close relation between thought, which is characteristically intentional, and perception, which is characteristically phenomenal, or consciousness itself. For example, rationalists such as Descartes held that all cognition is conscious, while empiricists such as Hume and Locke held that all cognition is grounded in perceptual experience. Later, Brentano, Husserl and the phenomenologists that they influenced conceived of intentionality primarily as a conscious phenomenon. Like the phenomenal intentionality theory, the views of these figures can be understood as taking a “consciousness first” approach. For more on the history of the phenomenal intentionality theory, see Kriegel (2013a) and the entry Consciousness and Intentionality.  