What is ‘certainty’ in our everyday life and work? AI changing what it means to ‘be certain’. For example, when we engage with others and are doing our work, we make judgments in which we ‘trust our instinct’. Are we still able to do so if we engage with the ‘certainty’ of the machine? How is ‘being certain’ in ‘dialogue’ affected by our conceptions of what it means to be human in interaction with the ‘machine’, and consequent distinctions between body and mind? Descartes first likened the human body to a machine (albeit a machine created by God) and endowed reason as being a transcendent universal instrument. La Mettrie proposed that language and culture separates humans from ‘animals’. However, in Diderot’s writing, ‘knowledge’ is seen as embodied, coming from our senses and language, and where gesture and rhythm evolve in practice. For D’Alembert, human ‘instinct’ is a skill, a learnt practice, and Rousseau believes that human certainty is something that cannot be measured. These questionings of the dichotomies of body and mind and human and animal, that relate practice and knowledge, also question the place and meaning of ‘rules’ of engaged practice. For Wittgenstein, one learns to make judgments through personal experience, ‘rules in practice’, whereby language is necessarily culturally situated and embodied, and calculation and Judgement are part of each other.