According to Peter Galison (1997), science has a highly fractionated structure with multiple sub-sub-disciplines, each with its own agenda. Cooperative trading between groups is necessary for most scientific work to move forward, and it is this trading that preserves the stability of science. We argue that it is not trading per se, but trading in a gift (as opposed to a commodity) economy that guarantees stability. We support our claims with an examination of contemporary work on magnetic resonance imaging instrumentation. Specifically, we consider: (1) How a feature improvement, intended to reduce scan time, led to substantial medical mis-diagnosis; (2) How a technical error, when corrected, created a consumer crisis in which radiologists preferred technically flawed instruments; (3) How new magnetic resonance theory radically altered the physical interpretation of MRI images; (4) How the MRI instrument at first was financially supported by, and--ironically--ultimately invalidated, the accepted understanding of the nature, source and management of chronic back pain. Ultimately there are three reasons stability requires gifting. First, without a general sense of shared purpose traders will not be committed to mutual engagement; profit does not provide an adequate shared purpose for the MRI community. Second, stability requires trust, and profits are not an adequate foundation for trust. Finally, knowledge is a gift that will not keep on giving if treated simply as a source of profit.