The doctrines have also been criticized by Sissela BokBok, pp. 35–7 and ff. and by Paul Ekman, who defines lies by omission as the main form of lying – though larger and more complex moral and ethical issues of lying and truth-telling extend far beyond these specific doctrines. Ekman, however, does not consider cases of deception where "it is improper to question" the truth as real form of deceptionsPaul Ekman, "Why Don't We Catch Liars?", Social Research, Vol. 63, No. 3 (Fall 1996), pp. 801–817. – this sort of case, where communication of truth is not to be expected and so deception is justified, was included by casuists.J.-P. Cavaillé, Ruser sans mentir, de la casuistique aux sciences sociales : le recours à l’équivocité, entre efficacité pragmatique et souci éthique, published in Serge Latouche, P.-J. Laurent, O. Servais & M. Singleton, Les Raisons de la ruse. Une perspective anthropologique et psychanalytique, Actes du colloque international « La raison rusée », Louvain la Neuve, mars 2001, Paris, La Découverte, 2004, p. 93–118 .
