If you have two million dollars in your bank account, that is also an intangible asset. Its physical representation is a series of numbers in the bank's database (and perhaps a number of backups of this database). You certainly can't touch it. Or I suppose, more accurately your wealth in this case is your bank's debt to you of two million dollars, which is an abstract notion of which the numbers in the bank database are the physical evidence.

Either way, whether you can touch this source of value seems like a moot point ;) Any economy is deeply based on trust.