Mars would almost certainly be an indicator, Lacellrein......but it's the chart as a whole that tends to reveal whether we are likely to be dreamers, thinkers or doers...and which of our available life paths we will most probably follow
unconsciously, whilst believing we are exercising freewill.
For example, my own chart (at
http://www.astrologyweekly.com/forum/album.php?albumid=143&pictureid=624 ) has Uranus on Gemini MC, both ruled by Mercury in Scorpio/2nd (which also rules the Virgo Ascendant/chart)....So, Uranus and Mercury point to a potential career as an astrologer......Nevertheless, I became an accountant...
...because Sagitarrius Mars conjunct Jupiter in Capricorn/4th (on IC and trine Saturn in Virgo/11th) drove me to seek a "safe, secure and well-paid" profession that my family/community would respect...
...Hence, astrology was always "destined" to be only a hobby for me...due to my psychological make-up.
EJ