A radio ad for new windows: "Dont you know that the dollars you spend for heatingare literally flying out the window."In the TLS (no less): "Broughams significance as a driving force for legal and educational reform cannot be underestimated." Im sure it can be; Ive been doing it all my life, and Ab esse ad posse valet illatio. [From actuality to possibility is a valid inference (whereas from possibility to actuality would not be one).]