As with other religions, most Buddhists are fundamentalists: most Theravadins believe most of the Pali Canon is the literal word of the historical Buddha; most Mahayanists believe most of the Mahayana Sutras are the literal word of the historical Buddha. 
 #Historians reject both these positions. 
 #In modern times there are plenty of Western-educated, non-fundamentalist Buddhists in the East. The Theravada ones claim the Pali Canon preserves the substance of the Buddha's teaching, a claim most historians wouldn't reject. The Mahayana ones claim the Mahayana sutras put the essence or spirit of the Buddha's teaching into new forms to suit changed circumstances, a claim I tend to think historians have no particular qualification to judge one way or the other. 
 #Remember the distinction made above: Buddhism, in the encyclopaedic sense intended for this article, is a collection of varied things. I'm not aware of anyone who'd say that Buddhism in this sense is philosophy, & it seems implausible that any informed person would do so. See Pure Land Buddhism, for example, & ask yourself whether anyone would call that philosophy. So that wording is misleading. 
 #Spirituality is just an aspect of religion, so that part of the statement seems rather pointless.