We discuss a generic mechanism for shear-thickening analogous to entropy-driven phase reentrance. We implement it in the context of non-relaxational mean-field glassy systems: although very simple, the microscopic models we study present a dynamical phase diagram with second and first order stirring-induced jamming transitions leading to intermittency, metastability and phase coexistence as seen in some experiments. The jammed state is fragile with respect to change in the stirring direction. Our approach provides a direct derivation of a Mode-Coupling theory of shear-thickening.When liquids are subjected to strong stirring, in general their viscosity decreases, a phenomenon known as 'shear thinning'. The opposite ('shear thickening') behavior when stirring leads to increased jamming is rather exceptional and intriguing [1]. That shear-thinning should be generic is quite easy to understand by considering the structure of any system having a large viscosity and long relaxation time scales. From the point of view of the phase-space energy landscape, the long relaxation times are the consequence of directions that are either almost flat, or contain barriers that can only just be crossed. When the system is stirred by non-conservative forces, displacements are easily induced along these directions, and this has the effect of speeding the relaxation. From the real space point of view, slow relaxations are linked to extended dynamically correlated spatial regions [2], and stirring tends to break off these domains, thus making the system more fluid. It is thus no surprise that just about any system (and any model) will naturally exhibit shear-thinning.For shear-thickening instead, several explanations have been attempted, and it is at present not clear whether a universal one will apply for all possible systems. There are indications that jamming in particulate suspensions is related to increased disorder [3], and in some cases to the formation of clusters of particles in lubrication contact [4,5]. To the extent that at large densities the strongly jammed state has the appearance of an amorphous, glassy solid, shear-thickening may be thought of as a consequence of an underlying glass transition induced by stirring [6]. For such collective behavior one can attempt a theory with less focus on the details but founded on notions that are thought to be generic of glasses: this has suggested, for example, the casting of the problem in a Mode Coupling format [6].In this Letter we attempt a microscopic setting in which glassiness and shear-thickening emerge naturally and are simultaneously understood. The basic idea is to exploit the analogy between entropy-driven transitions in which systems freeze upon heating and those in which they jam under the action of stirring. To obtain concrete results, we discuss this idea within the 'Random First Order' scenario for the glass transition, although it is not restricted to it. In its simplest version, the Random First Order scenario applies to models of fully connected degrees of free...