Philosophy Bites: Jonathan Birch on the Edge of Sentience
Date: October 21, 2024
Host(s): David Edmonds & Nigel Warburton
Guest: Jonathan Birch (London School of Economics)
Episode Summary Prepared by PodcastSummarizer.AI
Brief Overview
In this episode, David Edmonds and Nigel Warburton interview philosopher Jonathan Birch about the "edge of sentience"—the difficult and important question of which animals can experience feelings such as pain or pleasure. Birch, drawing from his project at LSE and his close collaboration with scientists, examines what sentience is, how it should influence animal welfare laws, and the challenges of determining sentience in less-studied animals like insects. The discussion covers philosophical, practical, and ethical aspects of animal consciousness and advocacy, focusing on the urgent policy implications of extending welfare to beings that may suffer.
Key Discussion Points & Insights
Defining Sentience: Beyond Pain and Pleasure
[00:42–03:05]
- Birch’s working definition: Sentience is "the capacity to have any positively or negatively valenced feeling" (C, 01:15).
- Not just pain and pleasure, but also emotions like joy, excitement, stress, and boredom are included.
- Valence: Birch clarifies as the positive or negative "quality" of experiences (C, 02:32).
- Positively valenced: pleasure, warmth, satiety.
- Negatively valenced: pain, boredom, fear.
Sentience vs. Consciousness
[01:36–02:26]
- Birch prefers “sentience” over the often broader and sometimes confusing term “consciousness.”
- Sentience refers to the most basic, evolutionarily ancient “base layer of... consciousness” (C, 01:55), not including higher-order reflection.
Ethical Stakes: The Practical Significance of Sentience
[03:13–03:58]
- Sentience crucially determines who deserves moral protection under animal welfare laws.
- Echoes Jeremy Bentham: “the question is not can they reason, nor can they talk, but can they suffer?” (C, 03:51).
Is Sentience a Matter of Degree?
[03:58–04:50]
- Birch rejects the idea of a linear scale:
- “I don't personally think one can talk of one animal being more sentient than another... I don't think we should be talking about more or less sentient as if there were a single sliding scale” (C, 04:06).
- Emphasizes diversity in sentient profiles and intelligence among animals.
The “Edge” of Sentience: A Tripartite Framework
[06:04–07:16] Birch describes three senses of the “edge”:
- Ontological Edge: The real, perhaps sharp or fuzzy, boundary between sentient and non-sentient beings.
- Epistemic Edge: The limit of our knowledge—where doubt about sentience arises (varies by individual).
- Practical Edge: Where laws or policies must draw a line, often forced into a binary decision.
Where Is the Real Edge?
[08:08–10:24]
- Birch argues humility is needed; we don’t know where the edge is in reality.
- Suggests shifting from “is this system sentient?” to “is this system a sentience candidate?” (C, 08:38).
- Sentience candidates: systems with a realistic possibility of sentience supported by credible theories and evidence.
- Includes all adult vertebrates and certain invertebrates (octopuses, crabs, insects).
- Reference to the “New York Declaration on Consciousness,” which signals plausibility of sentience in many animal groups—even insects.
Collaborating With Science: Synthesizing Evidence
[10:24–11:59]
- Birch’s project synthesizes scientific evidence (e.g. 2021 report for the UK government on cephalopods and crustaceans).
- Concludes strong evidence exists for treating octopuses, crabs, lobsters, shrimp as sentience candidates.
Bee Sentience and Individuality
[11:59–15:00]
- Birch insists on focusing on individual bee experience, not just collective hive behavior.
- Recent experiments show individual bees display remarkable learning and possibly even play-like behaviors.
- “The view that an individual bee is just a kind of reflex machine... has been completely smashed by the evidence.” (C, 12:53)
- Evidence mounts for emotional lives and possibly even pain responses in bees (self-protective grooming).
The Epistemic Edge: Uncertainty and Evidence
[15:00–16:57]
- Birch insists on a “realistic possibility” approach—“it becomes irresponsible to ignore that evidence” when deciding policy or farm practice (C, 15:58).
- Advocates erring on the side of caution—proportionality is key to determining the right level of caution.
The Practical Edge: Proportionality and Precedent
[17:22–18:22]
- Cautions against overestimating certainty or underestimating risk.
- “Give the animals the benefit of the doubt” (C, 17:25) and apply proportional measures.
- Supports citizen assemblies to establish what society deems proportionate animal protection.
Public Perceptions and Possible Change
[18:22–21:14]
- Often, it's not a “moral failing” but a lack of information that leads to lack of action (C, 20:56).
- Asks for more informed, reflective public debate—people show concern for their pets but may be unaware of suffering in food systems.
- Gives the example of boiling lobsters alive: evidence shows they suffer for 2 minutes, so stunning first is an ethically low-cost change (C, 19:10).
The Moral Significance of Death and Future Planning
[21:14–23:30]
- Is it morally wrong to kill a sentient animal painlessly if it’s unaware? Some argue only animals with a sense of the future are harmed by death.
- Birch is skeptical: relationships and implicit future orientation can matter; uncertainty about which animals have “plans” means we should be cautious.
Sentience and Moral Status
[23:41–25:08]
- Sentience is the key moral threshold, not intelligence.
- Sophisticated cognition might allow new forms of suffering, but doesn’t create a “VIP tier” of moral status (C, 24:05).
Policy Impact and Remaining Gaps
[25:08–26:26]
- Birch’s team influenced UK animal welfare law changes: “We advised them to amend [the animal sentience act] and include octopuses, crabs, lobsters, crayfish, and they did” (C, 25:28).
- More legal reforms (e.g. in slaughter practices) are still needed.
Overlooked Animals: Call for Greater Attention
[26:40–27:43]
- Fish and farmed invertebrates (especially in aquaculture and insect farming) are often neglected.
- “The things that just show absolutely no regard for the animals as sentient beings and would be so easy to change” (C, 27:18).
- Argues for quick, simple changes with massive impact on trillions of lives.
Notable Quotes & Memorable Moments
-
On why sentience matters:
“The question is not can they reason, nor can they talk, but can they suffer?... Sentience ends up having this huge ethical and policy significance.”
(Birch, 03:51) -
On scientific humility:
“We're currently not in a position to really know where the edge in the world is. And I think it's important to have a lot of humility about this.”
(Birch, 08:09) -
On bee cognition:
"The view that an individual bee is just a kind of reflex machine... has been completely smashed by the evidence.”
(Birch, 12:53) -
On the “precautionary principle”:
"We need to err on the side of caution. We need to, in some sense, give the animals the benefit of the doubt."
(Birch, 17:22) -
On proportionality:
“Our precautions need to be proportionate to the identified risks. They need to do enough without being excessive.”
(Birch, 17:50) -
On public ignorance and moral motivation:
“To me, it's not that there's a moral failing, really. In a way, people do care about animal welfare genuinely... The moral value is there, but what's not there is the information about how badly society falls short.”
(Birch, 20:56) -
On changes to UK law:
"We advised them to amend [the Sentience Bill] and include octopuses, crabs, lobsters, crayfish, and they did."
(Birch, 25:28) -
On overlooked suffering:
"There are things that just show absolutely no regard for the animals as sentient beings and would be so easy to change."
(Birch, 27:18)
Important Timestamps
- 00:51–02:26: Defining sentience and distinguishing it from consciousness
- 03:13–03:58: Why the concept of sentience matters practically and ethically
- 04:50–05:57: Is there a sharp or fuzzy cut-off for sentience?
- 06:04–07:16: Birch’s tripartite view of the “edge of sentience”
- 08:08–10:24: Scientific humility and “sentience candidates”
- 12:53: Bees as individuals with unexpected learning and emotional capacities
- 15:58: Justification for a precautionary approach in law and ethics
- 19:10: Ethical issues of boiling lobsters and how low-cost policy changes can help
- 23:41–25:08: Moral status: does intelligence matter beyond sentience?
- 25:08–26:26: Legislative impact and ongoing advocacy
- 27:18–27:43: Neglected animal welfare in new forms of farming
Tone and Language
The episode maintains a thoughtful, measured tone, with Birch consistently advocating humility, caution, and evidence-based policy. He challenges intuitive but unfounded assumptions, urges for greater public understanding, and balances skepticism with urgently practical ethics. Both interviewers maintain a respectful, probing style that helps ground the complex topic in everyday policy and moral choices.