TS2518: Aperture 3.5: Release notesLearn about Aperture 3.5: Release notes
Currently Being ModeratedNov 20, 2013 5:58 PM (in response to jester67)
The determining factor is not the system but the OS version. 3.5.x requires Mavericks, 10.9
Currently Being ModeratedNov 20, 2013 6:33 PM (in response to jester67)
You cannot, because your Mac is too old to run OS X Mavericks (it can't go above OS X Lion 10.7.5).
I think Aperture 3.4.5 is the highest version you can use with OS X Lion.