Platform is based on empty dogma (4)
I believe the answer is:
dais
'platform' is the definition.
(dais is a kind of platform)
'based on empty dogma' is the wordplay.
'based' becomes 'is' (I can't justify this - if you can you should believe this answer much more).
'on' means one lot of letters go next to another.
'empty' says to hollow out the word (remove centre letters).
'dogma' with its middle taken out is 'da'.
'is' put after 'da' is 'DAIS'.
'is' acts as a link.
Can you help me to learn more?
(Other definitions for dais that I've seen before include "Raised floor" , "stepping up here?" , "stand" , "Welshman's" , "Platform; podium" .)