see http://philpapers.org/survey/ for survey of philosophers about what they believe --- see http://www.moreintelligentlife.com/content/ideas/anthony-gottlieb/what-do-philosophers-believe for a summary in somewhat-non-philosophical language (^_^) ... e.g.:

Some 82% of the respondents accept or are inclined towards “non-sceptical realism” about the external world, which means they believe both that physical objects exist independently of the minds that perceive them, and that we can be said to know of their existence. Some 4.8%, though, are inclined to deny that we have certain knowledge of the existence of physical objects, and 4.2% accept or lean towards “idealism”, which is the theory that matter somehow depends on mind. As for the status of so-called “abstract” objects, such as numbers, the most popular view (scoring 39%, narrowly ahead of its closest rival) is “Platonism”, according to which abstract objects have a real existence independently of our minds.

- ^z -