automatic <P>

hello everybody !
i’d like to know how to write in raw PHP without wp’s automatic page settings : when writing a new post/page i leave a line blank, it makes me an automatic <P> (<p>blablabla</p>), and this gets on my nerves cause i absolutely don’t want it
i disabled everything i could in “writing options” and “personal options” (Use the visual editor when writing) and i tried to edit formatting.php
…without success
thanks