A few more thoughts:    
     All investment is not alike.  That is, investment which implements 
innovations is of a different nature than investment that simply  
replicates what already exists.  The latter must precisely keep pace 
with population growth for a society just to remain in the same place. 
But innovation that improves productivity uses investment dollars 
(or time or whatever) more efficiently:  that is, the contribution 
to economic growth is greater than simply replacing worn-out  
capital with an identical counterpart. 
     And to echo others, the negative impact of investment to spur 
growth must be taken into the calculation as well -- we have to 
be far more aware of implicit and long-run costs that are left off 
the enterprise balance sheet, are difficult to calculate, but are 
significant if growth is to be equated with wellbeing. 
     ------------- 
     The other point is that if there is no reason for the government 
to favor savings over consumption, and likewise no reason to favor 
consumption over savings -- in terms of the government's behavior 
in the economy -- then we can think of the redistributive effects 
of government activity as simply that: redistributive effects. 
     Lesson One of the New Deal, for example, is that it failed to 
pull the United States out of the Great Depression. 
     But Lesson Two is that it saved individuals - people -- old 
people, children, families -- from utter destitution.   
     Suppose that the New Deal (as an example) was neutral in terms 
of its macroeconomic effects.  Then it becomes a matter of social 
values whether it is right to tax the comfortable to prevent the 
children and the elderly from starving (quite literally).  We might 
quibble over the efficiency with which we could meet that goal.  But 
the argument that redistributive policies are perverse because they 
dampen economic growth has far less merit than the classical economists 
or the current crop of Chicago neoclassical economists believed.  And 
perhaps you do not NEED Keynes' hopeful analysis that redistributive 
policies would do a better job of encouraging growth than those 
promoting savings (and hence favoring the wealthy, as has been pretty 
much agreed upon by economists for over a century, as having a greater 
propensity to save portions of their income than the poor.  We might 
add that it also favors the senior population over young parents, too.) 
     -- Mary Schweitzer