Unlike ancient Greece where personalvirtue was the route to fulfillment, mod-ernmantypicallyseekstoimprovehumanwell-being by external means, in a processknown as the medicalization of society.The apparent novelty of recent proposalsin psychological theory to develop charac-ter strength, therefore, lies in their reem-phasis on a personal implementation ofpositive values (Peterson and Seligman,2004). Among the factors contributingto a new look at self-determination hasbeen the capacity for the neural sub-strate to selectively alter itself via neuro-plasticity. Indeed, the confluence of pastand contemporary thinking may presagea consideration of neurobiological instan-tiation within which virtuous behaviormaybeenhancedinaccordwithprinciplesgoverning neuroplastic change.But what are virtues and positive traits?And to what extent can these concep-tions inform our growing understand-ing of the neural contribution to humanbehavior? Presupposed in such questionsis a conceptual ground needed to define acorresponding empirical terrain (Bennettand Hacker, 2003), without which suchinformation would lack coherence andconclusive power. Accordingly, positivepsychology identifies a positive trait asa “disposition to act, desire, and feel”involving the exercise of judgment andleading to a recognizable human excel-lence’ (Park et al., 2004). The concise, butmore precise formula of Aquinas, “habi-tus operativus bonus,” is similarly con-ceived (Hibbs, 1999). Anglicized, habi-tus connotes habit, often considered acompelling behavioral pattern reinforcedthrough repetitive activity, but in anAquinas context also evinces a free-dom associated with the deploymentof a skill acquired and honed throughrepeated engagement. Operativus, under-stood to mean operationally effective,connotes stability and continuity, a dis-position to future performance. The thirdterm, bonus,grants an orientational normmore precise than the analogous “rec-ognizable excellence” and that Aquinasgrounds in right reason and love ofneighbor. Accordingly, we will employthe construct “habitus operativus bonus”rather than “positive traits” in the ensuingdiscussion.A priori, habitus tacitly acknowledgesa behavior’s dependence on repetitiveengagement. This acknowledgement hasreceived much confirmation from empir-ical studies of patterned behavior; andmany of the physiological, cellular, andmolecular features have now been elu-cidated. Originally theorized by Hebb(1949) as an activity dependent synap-tic strengthening, this interpretationwas subsequently confirmed by Lomo’sdiscovery (Lomo, 2003)ofthelongtermpotentiation effect (LTP). In the Hebbianscheme synaptic strength is enhanced bycoincident, and repetitive, neural activ-ity. The molecular details of this effectentail a host of short term, cell signalingand, when sufficiently stimulated, longterm, transcriptional and cell restructur-ing mechanisms (Benfenati, 2007). Theformer involve an enhancement of Cainflux at both pre and post synaptic sites,together with a corresponding activationof Ca dependent protein kinases, last-ing minutes to hours. The latter involvea wholesale restructuring of synapticcontacts that can potentiate enhancedsynaptic efficiency for days and evenmonths. A key mechanism in transcrip-tionalup-regulationisthekinasemediatedactivation of the CREB set of activatorand repressor proteins. The stabilization,and proliferation, of coordinated synap-tic activity, thereby, increasingly routsinformation flow through select circuitpathways.These observations confirm three con-clusions that follow from the classic for-mulation. First, they show that habitualactivity is needed to enhance synapticstrength. Second, the behavioral perfor-mance or skill is made more easily opera-tive. The freedom spoken of by Aquinas isthusneurallyprovidedforintheenhancedinformation flow through the behavioralcircuit. Finally, the ease of flow facilitates