From the Stray Thought Bin - Watch Your 'Philosophizing'

If you want to go higher and higher,

with your head floating up in the clouds,

Head_in_the_Clouds_by_AndrewDickman
http://fc07.deviantart.net/fs5/i/2004/340/1/f/Head_in_the_Clouds_by_AndrewDickman.jpg

make sure that your legs are well-tethered,

to keep both your feet on the ground.