Freedom and ethics: Benjamin Libet’s work Jorge Alberto Álvarez Díaz Abstract A fundamental idea to sustain basic ethical concepts such as autonomy, responsibility, etc., is “liberty”. The determinism/freedom aporia has been present in philosophical tradition since ancient world. However, after the development of neuroscience, it has been argued that freedom is merely an illusion and human beings are neurobiologically determined in our actions. This paper presents the pioneering work of Benjamin Libet on this subject (an approach that used electroencephalography and electromyography), also a critique on Libet interpretations of his results. Keywords: Bioethics. Neurosciences. Philosophy. Resumen Libertad y ética: el trabajo de Benjamin Libet Una idea fundamental para sostener conceptos éticos fundamentales, tales como el de autonomía, respon- Update Articles Update sabilidad etc., lo es la “libertad”. La aporía determinismo/libertad ha estado presente en la filosofía desde el mundo antiguo. Sin embargo, tras el desarrollo de las neurociencias, se ha planteado que la libertad es una mera ilusión y que los seres humanos estamos determinados neurobiológicamente en nuestro actuar. Este trabajo presenta los trabajos pioneros de Benjamín Libet sobre este tema (una aproximación que utilizó elec- troencefalografía y electromiografía), a la vez que realiza una crítica sobre las interpretaciones del propio Libet. Palabras-clave: Bioética. Neurociencias. Filosofía. Resumo Liberdade e ética: o trabalho de Benjamin Libet Uma ideia fundamental para sustentar conceitos éticos fundamentais, tais como autonomia, responsabilida- de, etc., é a “liberdade”. A aporia determinismo/liberdade tem sido presente na filosofia desde o mundo an- tigo. No entanto, após o desenvolvimento da neurociência, tem-se argumentado que a liberdade é uma mera ilusão e que nós seres humanos estamos neurobiologicamente determinados em nossas ações. Este artigo apresenta os estudos pioneiros de Benjamin Libet sobre este assunto (una abordagem que utilizou eletroen- cefalografia e eletroneuromiografia), enquanto realiza uma crítica sobre as interpretações do próprio Libet. Palavras-chave: Bioética. Neurociências. Filosofia. Doutor [email protected] – Universidad Autónoma Metropolitana, Unidad Xochimilco, DF/México. Correspondência Edificio A, 2º Piso. Área de Postgrados en Ciencias Biológicas y de la Salud. Calzada del Hueso 1.100, Colonia Villa Quietud, Delegación Coyoacán CP 04960. DFQ/México. Declara não haver conflito de interesse. 432 Rev. bioét. (Impr.). 2014; 22 (3): 432-8 http://dx.doi.org/10.1590/1983-80422014223025 Freedom and ethics: Benjamin Libet’s work Neurophilosophy It seems that the moderate positions would be more plausible, rich and successful in their the- oretical and methodological contributions. So, if The term “neurophilosophy” was introduced you are going to talk about a neurophilosophy, we by Patricia Smith-Churchland, Canadian philoso- should speak of the branches of classical philosophy pher, in a text that is now obligatory reference to with the prefix “neuro”, with the aim of highlighting address the issue 1. In it, Churchland proposes a sys- this new approach, so you can speak of a neuroepis- tematic view of the neurophilosophy, the first appe- temology 7, a neuroethics 8 etc. It has been written aring in the history of philosophy and in the history a lot about the latter; in fact, perhaps the greatest of neuroscience. This view would be, very syntheti- attention was in the neurophilosophy branch so far cally, to support the radical biologistic materialism: (even, probably more than in neurophilosophy it- any mental state can be reduced to a brain state and self). Possibly this is due to it has been stressed that thus it is possible to fully explain it. Thus, the pale- with the neuroscientist advance we should perhaps ophilosophy should be abandoned to make way for rethink issues of far-reaching and extensive philo- the neophilosophy, a neurophilosophy that actually sophical tradition, such as consciousness, freedom, ends up being diluted when the neurosciences can and responsibility 9. fully explain the issues that traditionally philosophy Articles Update These themes are necessary and unavoidable have addressed from the ancient world (memory, if you want to treat seriously the issue of ethics: we learning, consciousness, free will etc.). must speak of a moral conscience, the possibility Although Churchland had (and still has) fai- of freedom and responsibility to address the issue thful adherents to his position, he has also had se- of ethics. Thus, in this paper the work of a neuros- rious detractors. One of them was Gunther S. Stent, cientist on the theme of freedom and some possible renowned molecular biologist, who after the appe- implications that could have effects on ethics is dis- arance of the text of Churchland published a review cussed. which considers that the monistic position adopted does not explain everything that it seems to want to explain 2. Subsequently, Stent published another Benjamin Libet work where he exposes that exist unique characte- ristics of human life that can not be reduced to a Benjamin Libet was born on April 12, 1916 in neurobiological explanation, such as the moral life3 . Chicago, the first child of a couple of Jewish immi- 10 The radical stance of Churchland is not alo- grants from Ukraine . His father and grandfather ne in the field of neurophilosophy. There are other were tailors and didn’t speak English, so that Ben- views of what should be the neurophilosophy that if jamin had to learn it in the streets of the West of it was a discipline (subject that is beyond the scope Chicago, populated primarily of Jewish and Italian of analysis in this text), it should be raised that is immigrants. under construction. These other visions would not In 1936 obtained his degree at the Univer- be radical, since they would not reduce all own and sity of Chicago and in 1939 his PhD in physiology fully human life to the activity of the neuronal cir- (with Ralph W. Gerard). He did postdoctoral work cuits, but they would agree that neuroscientific ad- between 1939 and 1945: at Albany Medical Colle- vances must be taken into account when developing ge (1939), the Institute of Pennsylvania Hospital a philosophy. (1940), the University of Pennsylvania School of Me- dicine (1943), his alma mater, where he meet again Probably the most developed stance in this with his mentor (1945) 11 . regard is the one of Georg Northoff, who has in- teresting works where he tries to define what He came to the University of California, San neurophilosophy would be4 and what could be its Francisco in 1949, where he was Professor Emeri- methodology 5. In fact, it is appreciated for the ideas tus from 1984. In 2003 received in its first edition, in this paper, as many who believe the neuroscien- the “Virtual Nobel Prize in Psychology”, awarded by tific knowledge must be taken into account when the University of Klagenfurt (Austria), for his pioneer drafting philosophy, just do not say how. Northoff achievements in the research of consciousness, ini- 12 elaborates a theory that emerges from the recog- tiation of the action, and free will . nition that the inclusion of subjective experience or After the influence of Sir John Eccles 13, Libet first person perspective 6 in developing a neurophi- investigated the synaptic and postsynaptic res- losophy. ponses, drifting his interest gradually towards the http://dx.doi.org/10.1590/1983-80422014223025 Rev. bioét. (Impr.). 2014; 22 (3): 432-8 433 Freedom and ethics: Benjamin Libet’s work electrogenic mechanisms 14-16, field that did not (the wrist flexion) preceded the attainment of such abandon. In the 1970’s he became involved in the movement. This could easily be interpreted as a cor- research of the neuronal threshold activity and fe- respondence between brain events and the subjec- elings. His initial researches involved the determi- tive experience of the research subjects. However, nation of the amount of activation at specific sites what attracted wide attention of Libet’s team (whi- in the brain required to trigger the artificial somatic ch remains striking, regardless of the position to be sensations, based on routine psychophysical proce- taken on the issue of freedom) were the results of dures. This work soon crossed into research on hu- the objective tests. They found that the readiness man consciousness, and its famous experiments on potential appeared between 300 and 500 ms befo- the neurobiology and freedom. re the subject had the conscious perception of the desire to flex the wrist, W. Data were collected and reinterpreted by Libet himself, who said: The Libet experiment The freely voluntary acts are preceded by a speci- We must remember that Hans Berger begins fic electrical change in the brain (the ‘readiness po- tential’, RP) starting 550 ms before the event. The Update Articles Update the studies in electroencephalography in humans in the 1920s. The improvement of technique and the human subjects come to realize that the intention standardization made progress in this field. In 1965 of acting 350-400 ms after the beginning of the RP, Hans Helmut Kornhuber and Lüder Deecke discove- but 200 ms before the motor act. Accordingly, the red what they called in German as “Bereitschafts- volitional process starts unconsciously. But the cons- potential” 17, In English is translated as “readiness cious function could still control the outcome, as it potential”, while in Spanish it is translated as “po- can veto the act. The free will, therefore, is not exclu- tencial de preparación” or “potencial de disposici- ded. These findings put restrictions on the views of ón”. Moreover, in the 1960s also the clinical use of how the free will can operate; it would not initiate a electromyography was generalized. voluntary act, but could monitor the performance of the act. The results also affect the views about guilt With this background, the Libet team had tech- and responsibility 22.