If the government increases its funding for civilian scientific research, private patrons and industries will believe that such research has become primarily the government' s responsibility. When they believe that research is no longer primarily their responsibility, private patrons and industries will decrease their contributions toward research. Ttherefore, in order to keep from depressing the overall level of funding for civilian scientific research, the government should not increase its own funding.
An assumption on which the argument relies is that any increase in government funding would displace more private funding for funding for civilian scientific research than it would provide.